BioAtla, Inc.

Please stand by, your program is about to begin. If you need assistance during your conference today, please press star zero. Good day everyone and welcome to today's BioAtla fourth quarter and fiscal year 2024 earnings call. At this time all participants are in a listen only mode. Later we will have the opportunity to ask questions during the question and answer session. You may register to ask a question at any time by pressing star one on your telephone keypad. You may withdraw yourself from the queue by pressing star two. It is now my pleasure to turn the conference over to Mr. Bruce Mackle of Lifesight Advisors. Please go ahead, sir.

Thank you, operator and good afternoon everyone. With me today on the phone from BioAtla are Dr. Jay Short, chairman, CEO and co-founder and Richard Waldron, chief financial officer. Following today's call, Dr. Eric Sievers, chief medical officer and Sherry Lydic, chief commercial officer will join Jay and Rick in a short Q and A. Earlier this afternoon, BioAtla released financial results in a business update for the fourth quarter and full year and did December 31, 2024. A copy of the press release and corporate presentation are available on the company's website. Before we begin, I'd like to remind everyone that statements made during this conference call will include forward looking statements, including but not limited to statements regarding BioAtla's business plans and prospects and whether its clinical trials will support registration, plans to form collaborations and other strategic partnerships for selected assets, results, conduct, progress and timing of its research and development programs and clinical trials, expectations with respect to enrollment and dosing in its clinical trials, plans and expectations regarding future data updates, clinical trials, regulatory meetings and regulatory submissions, the potential regulatory approval path for its product candidates and expectations about the sufficiency of its cash and cash equivalence to fund operations and expected R&D expenses. These statements are subject to various risks, assumptions and uncertainties that can cause actual results to differ materially and are described in the filings made with the SEC, including the most recent annual report on form 10K and subsequent quarterly reports on form 10Q. Your cautions not to place undue reliance on these forward looking statements, which speak only as of today, March 27, 2025 and BioAtla disclaims any obligation to update such statements to reflect future information, events or circumstances, except as required by law. With that, I'd like to turn the call over to Dr. Jay Short.

Jay. Thank you, Bruce. And thanks to everyone for joining us for our fourth quarter and full year 2024 BioAtla earnings call. Additional details related to what we will share today are available in today's press release and our updated company presentation, which are available on our website. Also the posters, which were recently presented at the Mayo Multidisciplinary Head and Neck Cancer Symposium and the European Lung Cancer Congress on our phase two assets, Xerifetumab Vedotum or Osve and Macbotumab Vedotum or NECV respectively are also available on our website. I will begin with updates on our conditionally active biologic or CAB platform clinical programs that we are advancing internally at BioAtla. All of these CAB based programs are designed to efficiently increase the potency and safety of our therapeutic candidates targeting solid tumors in areas of high unmet medical need. Beginning with our first in class dual conditionally binding CAB, EpCam and CAB CD3 bispecific T cell Engager antibody. EpCam is an attractive therapeutic target because it is widely expressed in most solid tumors. However, it has been a difficult target to drug with traditional antibody technologies because it is also widely expressed in normal epithelial tissues. EpCam's ubiquitous expression in both tumors and normal tissues makes it generally undruggable without a differentiating technology like CABs. Successfully enabling the selective targeting of solid tumors with CAB technology offers the potential for developing one of the first pan cancer therapies outside of immune checkpoint inhibitors. Today, our dose escalation is progressing well. As hoped, the maximally tolerated dose has not yet been reached and multiple patients are already experiencing tumor reduction including one colorectal cancer patient with continued stable disease for more than one year. At present, three patients have received the target dose of 100 micrograms weekly. Two of these three patients have already cleared the dose limiting toxicity period and the third patient is on track to clear the DLT period on April 8th. We are now also screening patients for the next cohorts who are anticipated to receive the target dose of 300 micrograms. Details about the dosing schematic can be found in our corporate deck. It's worth noting that animal modeling data indicate that significant tumor reduction is expected to occur at target doses of approximately 200 micrograms and above. So we believe that we are reaching exposures where we will start observing formal objective responses. We remain on track for a data readout of the dose escalation portion of the study in mid 2025. We also anticipate a data readout for the cohort expansion portion of the study in the first half of 2026. CAD T-cell Engager BISpecifics represent a novel approach to harnessing the body's immune system to target and destroy cancer cells, offering the promise of more precise and effective treatment options for cancer patients. We believe our dual CAB, EpCAM, and CAB CD3 T-cell Engager has potential to be at the forefront of this exciting and powerful approach and has the potential to treat a wide range of metastatic tumors, including cancers of the colon, lung, breast, pancreas, and prostate, among others. Now moving on to CAB Axil ADC McVee. Last quarter, we announced that we are observing ongoing anti-tumor activity with multiple confirmed responses among 21 available patients with tumors expressing NK RAS across nine different KRAS mutations. As part of today's update, we are excited to share promising results from the 1.8 Mg per Kg Q2W dosing cohort from the 16 available patients in this cohort. We have observed multiple confirmed responses across different MK RAS variants, while also demonstrating and encouraging clinical benefit risk profile, as well as a patient who had a prior failure of SotoRAS who experienced a partial response. In addition, a patient who achieved a complete response remains in complete response now for over two years. Importantly, our initial findings for overall survival continue to be compelling, as we are now seeing an exceptional overall survival with 66% and 58% of patients with MK RAS non-small cell lung cancer alive at a landmark of one year and two years respectively, which we believe exceeds what has been observed with the standard of care. The median overall survival has not been reached at 35 months from the first dose, with continued follow-up ongoing. MIECHV is associated with a generally well-tolerated safety profile, both with and without novolumab, and no new safety signals have been identified. Notably, the drug-related treatment discontinued patient rate was only 7%. We are presenting these data at the European Lung Cancer Congress and encourage you to visit the poster on our website. Based on our evaluation of patients with mutant K-RAS non-small cell lung cancer, we continue to observe a high correlation of Axl and MK RAS expression, and believe the mechanistic link between Axl and MK RAS that drives tumor resistance, coupled with the exceptional overall survival that we are seeing in the Q2W dosing cohort, supports a potential anti-Axl pan MK RAS strategy. Now I'd like to pivot to the phase two clinical programs that we are currently advancing toward corporate partnerships, beginning with our CAB-1280C, OSV, which is being evaluated as a monotherapy in treatment refractory head and neck cancer patients. Last quarter, we reported an emerging clinical profile in treatment refractory patients with a median of three prior lines of therapy, with the potential to become the standard of care in the second line cancer patients. Plus head and neck cancer population. Additionally, we shared that we received a fast track designation and actionable guidance from the FDA on our proposed randomized pivotal trial design with Osvi monotherapy, versus investigators choice among patients with recurrent or metastatic head and neck cancer with disease progression on or after platinum based chemotherapy and PD-1 antibody therapy. As part of today's update, the fully enrolled phase two study using Osvi monotherapy continues to demonstrate new responses in treatment refractory second line plus head and neck cancer at the 1.8 Nick per Kg Q2W dosing regimen. We also continue to capture efficacy data for several endpoints, including overall response rate, duration of response, progression free survival, and overall survival. A particular interest is that we have observed a compelling signal in patients with metastatic HPV positive head and neck cancer, who represent a high unmet need as they are poorly served by agents that inhibit EGFR. These new data, as well as evolving data in the overall head and neck cancer cohort, were presented as a poster today at the Mayo multidisciplinary head and neck cancer symposium. To highlight among the 11 patients with HPV positive head and neck cancer treated with 1.8 Nick per Kg Q2W, there was 100% disease control rate, a 45% overall response rate, and so far a 27% confirmed response rate with a duration of response greater than 5.3 months that is ongoing. Multiple patients remain on treatment and have the potential to have responses that deepen with time. It is noteworthy that an HPV positive patient achieved a complete response that continues in complete remission, now at greater than 16 months and ongoing. We believe OSV, especially at the 1.8 Nick per Kg Q2W dose has been remarkably well tolerated, and there are no new identified safety findings. Further, these results of HPV positive head and neck cancer are mechanistically supported by recent literature showing that HPV associated oncogenes upregulate war II expression, drive proliferation and invasiveness, thus now providing a compelling rationale for also targeting war II and cancers associated with human papillomavirus infection. We believe our extended experience with Q2W dosing of OSV also has the potential to satisfy Project Optimus requirements, and we plan to share our results with the FDA to seek confirmation regarding our proposed recommended phase III treatment regimen. We are encouraged by the differentiated findings in second line plus head and neck cancer patients, particularly in both HPV negatives and HPV positive patients. For partners, this second line plus population represents a worldwide commercial opportunity of greater than $1 billion in peak sales with upside opportunity in the first line setting, as well as in other HPV positive cancers. Moving now to our CAHV C2OA4 antibody, a Voustatug. A Voustatug is similar to IPPE with respect to epitope, affinity, and half-life, but differs from IPPE with respect to its ability to avoid binding in the normal tissue environment. As part of today's update, we have dosed a total of 12 patients with unresectable and or metastatic melanoma, eight of whom received five mics per Kg, three were dose escalated to 10 mics per Kg, and one dose escalated all the way to 14.3 mics per Kg. While we continue to observe compelling anti-tumor activity with a differentiated safety profile, 10 of the 11 available patients show tumor reduction, and with the 11 showing no growth to date. Of these 11 available patients with unresectable and or metastatic melanoma treated with a Voustatug in combination with the PD-1 antibody, so far we observed across multiple doses an overall response rate of 64% and disease control rate of 100%. Notably, we observe a partial response in a patient with acral subungle or under the fingernail melanoma, which is a rare and difficult to treat form of melanoma that generally has a poorer prognosis than contiguous melanoma. The safety profile of a Voustatug continues to be differentiated with a relatively low incidence and severity of immune-mediated AEs, particularly among patients who receive five mics per Kg for less than or equal to 18 weeks, in a total of 17 patients. Focusing on these 17 patients, we observed 18% grade three immune-mediated adverse events and no grade four events, while maintaining strong efficacy. This safety profile compares favorably to ipilimumab with a reported rate of 40% grade three and four immune-mediated adverse events. We believe a Voustatug has demonstrated a differentiated clinical profile relative to other CTA-4 antibodies and has the potential to be best in class. As such, we have recently initiated partnering discussions with the intent to align with a partner that can maximize the value of this asset. Onto our ongoing clinical communications. I am pleased to report our progress with the medical and scientific communities, as acknowledged with numerous publications and presentations at prestigious conferences, including the European Lung Cancer Congress, Mayo Multidisciplinary Head and Neck Symposium, and the American Society of Clinical Oncology. Finally, for our corporate updates, BioAtlet is further extending our runway beyond key clinical readouts in the first half of 2026 by streamlining and realigning resources, which includes a workforce reduction of over 30%. We estimate that we will incur approximately $0.6 million of one-time cash payments related to the workforce reduction, which will mostly be paid in the second quarter. We intend to retain all employees essential for advancing our two internal priority programs, as well as supporting partnering of other clinical assets, which are improving with the ongoing data readouts. I also wish to express my deep appreciation and respect to our employees, both past and present, who have contributed so much with their creativity and hard work to advance these important cures for patients. With that, I would now like to turn the call over to Rick to review the fourth quarter and full year 2024 financials. Rick?

Thank you, Jay. Research and development, that is R&D, expenses were $11.6 million for the quarter ended December 31, 2024 compared to $22.7 million for the same quarter in 2023. The decrease of $11.1 million was due to lower clinical development expenses in 2024 from the lower overall targeted enrollment across our clinical trials in 2024, resulting from our program prioritization in 2023. We expect our R&D expenses to continue to decrease overall in the first half of 2025 due to our recent restructuring and as we complete phase two trials for several indications and focus our ongoing development on our prioritized programs. General and administrative expenses were $4.6 million for the quarter ended December 31, 2024 compared to $5.9 million for the same quarter in 2023. The $1.3 million decrease was primarily due to lower stock based compensation, personnel related costs and D&O insurance premiums. Net loss for the quarter ended December 31, 2024 was $14.9 million compared to a net loss of $26.9 million for the same quarter in 2023. Net cash used in operating activities for the whole year ended December 31, 2024 was $72 million compared to net cash using operating activities of $104 million for the same period in 2023. Cash used for the quarter ended December 31, 2024 was $7.5 million. Cash and cash equivalents as of December 31, 2024 were $49 million compared to $111.5 million as of December 31, 2023. Excluding any potential future milestones, we believe that cost reductions to be subsequently realized from the realignment of resources and focus on our two internal priority programs further extends our runway beyond key clinical readouts in the first half of 2026. And now back to Jay.

Thank you, Rick. We are encouraged by the clinical outcomes observed from our evolving CAB program data sets, which continue to be differentiated in some of the most challenging solid tumor types. As a result, we continue to advance multiple discussions with potential collaborators on our phase two assets, as well as initiate new ones. We believe the compelling results we are obtaining will serve as important catalysts, including our EpCam T-cell Engager program, and have the potential to be transformative for our patients and shareholders alike. Thank you for your attention and continued support. With that, we will turn it back to the operator to take your questions.

Thank you. At this time, if you would like to ask a question, please press star one on your telephone keypad. You may remove yourself from the queue at any time by pressing star two. Once again, that is star one to ask a question. We will pause for a moment to allow questions to

queue. And we will go first to Jeet Mukherjee

at BTIG.

Great, thanks for taking the question. So just in terms of the partnered programs, I noticed in the corporate decade, you mentioned the ROAR 2 program is in the process of partnering, while CTLA-4 is initiating partnering. Could you perhaps just give a bit more color on where you are on these discussions, and what's perhaps needed to get one or both across the finish line? Thank you.

This is Jay. We have both advanced discussions and newer discussions. This HPV positive data is pretty new to most of the people we're in discussions with, except for just a small number. So we also expect additional interest prior to this report. So we're pretty encouraged with the discussions that are underway. And so I think it covers a range, and I'm expecting some new participants to get involved as well. Because I think this has been a significant problem in the treatment of head and neck cancers, being able to add in effective treatments in these refractory HPV positive patients.

Understood. And maybe if I could just ask a follow-up for the Axel program. I believe last time you were still analyzing some patient samples for both Axel and KRAS expression. So in your hands, what percentage of patients are double positive for mutant KRAS and Axel? And have any patients on the study today been treated with a pan-RAS inhibitor? Thank you.

I'll share some of this question with Eric. I'll just start off by saying, in our immunohistochemical analysis, we saw a bit over 70% that were positive across all types of MK-RAS mutants. And I think the G12C was, I think, 100%. Also, we know that if you look at mRNA levels, that it's much, much higher than even that. So it's a very strong correlation, keeping in mind that mRNA is likely to be more sensitive than immunohistochemical data. But it's a very strong correlation, and further, there's a fundamental mechanistic alignment. You'll see, if you look, refer to the corporate deck, you'll see that laid out there on slide 23 within that deck. Eric, you wanna add anything to this?

Sure, thank you, Jay, and thanks for the question, Jade. On slide 24, we indicate that one of the patients had prior treatment with Sodoracid, and they did experience a response. And we did not treat anyone with a known prior exposure to a -K-RAS inhibitor, which was your

question. Thank you. We will move next to Kelly Shi with Jeffreys.

Hi, this is Hanfei for Kelly. Thanks for taking my question. As in your term data coming up with BA3182, just curious what kind of data we're expecting, and have you reached a recommended phase two dose, and what we're looking for in the next follow-up of data and expansion for you? I think that's a good portion of the study. Thank you.

Eric, you wanna take that one?

Sure, thank you, Kelly. I appreciate the question. On slide 19 of our recently released corporate deck, we have the BA3182 dose escalation schema. So just to remind everyone, this is the EpCam targeted T-cell engager where it's conditionally binding both on the EpCam arm and the CD3 T-cell binding arm to really drive the therapeutic window even further to benefit. This gives you a sense of the dose escalation. We've achieved cohorts A1, B1, and B2, and then we're moving up with a one-step priming dose and a two-step priming dose. We're doing that concurrently, and you can see there's a schema for cohorts C and D that are both enrolling concurrently. And you asked about the recommended phase two dose. We think we're in a zone where we're seeing meaningful tumor control, and as the animal model suggests that tumor reduction would occur right around 200 micrograms given weekly. It's really consistent with that. So we're enthusiastic to be able to report more fully on this phase one data set in the coming months. I'll note that two of the three patients in cohort C4, as you see on the slide, have already cleared the DLT observation window, and the third patient will clear very shortly, as Jay just

mentioned, in early April. We'll move next to Ren Benjamin with Citizens.

Hi, this is Sam. I'm for Ren. Just a quick one on 3182 as well. Are there any partnership discussions ongoing for this asset, and if so, are these contingent upon the Med25 data?

Sure. You want to touch on that one?

Sure. Sure. Hi, there. Thanks for the question. We currently have had interest in this program. You know, our goal is to get through phase one and also the expansion cohorts so that we have a data set that can really drive a lot of value for this program. So while we've had interest, you know, we're not at a point where we necessarily would engage with the data set and engage in discussions until we have a look at what the dose expansion, what the dose escalation and expansion data look like.

Got it. Thank you for the call.

And once again, if you would like to ask a question, please press star 1 on your telephone keypad. We will go next to Tony Butler with Rodman and Rinshaw.

Thanks very much, Eric. Eric, one question on the HPV-positive patients for the head and neck cancer program. Were all of those patients that responded smokers? That's actually somewhat important. And second, Jay, you had mentioned a partnering program, but in the deck, again, it makes reference to moving toward discussions with mid-tier companies. And I just wonder why that strategy or is it in fact an argument such that the market opportunity may be somewhat smaller than a large pharma would engender and a mid-tier company would like very much. Thank you.

Why don't I start with the last one and then we'll go to the other one. We think that it's a billion dollar opportunity over a billion dollars in the second line. And so we did experience one larger company that indicated that they were wanting a multi-billion dollar opportunity. And so we recognize from that discussion that maybe we'll add in more of the mid-tier companies and that's really where that's derived from. But let's face it, a billion dollar opportunity in a refractory patient population with a fairly efficient trial and a big differential from the standard of care is still pretty exciting. I would also note even in the HPV positive subpopulation, it's over a half a billion, the risk adjusted. So I think either way you've cut it, it's pretty good. You still have the opportunity to advance to first line, have the opportunity to advance to other indications as well. So, but you're right in this regard, Tony, that we said we recognize that adding in some of these mid-tier players matters and actually I would say it does matter because we're seeing some people that have capital that have really not been able to perform with their late line drugs and are very interested in getting into some strong phase two compounds that can be too efficient phase three. So hopefully that helps address some of it. Good thought, thank you, Jay.

Hey, Tony, so you have a really interesting question about smokers amongst the patients that have the P16 positive protein, the HPV analysis. We have a total of 26 patients in this that had the HPV of 40 total. And as you know, the HPV negative patients were really more associated with smoking and alcohol exposure, the environmental exposure form. And HPV is much more the oncogene driven side with a particular unmet need amongst patients when they reached second and third line setting because the lack of EGFR benefits. And I don't have the smoking correlation set up, but that's something I can try to obtain for you after the call, so thank you.

I appreciate that. You know, the key is whether it's smokers and non-smokers. That's really where I wanna go with that HPV positive cohort, thank you.

Yes, we have the smoking data. It's just we haven't made a correlation with the HPV, but it's a great question and we'll get right on it.

Thank you. Thank

you. We'll move next to Arthur He with HC Rainway.

Hey, good afternoon, Jay and team. Thanks for taking my question. So I guess I have three quick questions. So first for the F-CAM program, regarding the data coming the mid of this year, is that which kind of dose level of the data we can see? Can we go up to the 3300 micrograms, sorry, micrograms, the cohort data, or is probably more at the lower dose levels?

Well, certainly the 300 we should have, assuming all the dosing goes well. Is there a chance to see 900? Possibly if we do it in July, so we'll just make sure, it also depends a little bit on patient recruitment, but I'm very comfortable that the 300 will be there and potentially higher.

Gotcha, so Jay, when you're talking about 300, you mean 300 from both C and D arms or just the C? No, I'm

talking about C. I think the D formally is just behind the other, but tends to reinforce, but yeah, I'm focused on C right at the moment.

Gotcha, thanks for that. And my second question is regarding the EXCEL program. So maybe correct me if I was wrong. So are you guys going to treat more patients in terms of the EXCEL program? Or I mean, is there any more additional patient data we can see from in the future?

I think our hope, I mean, EpiCAM is a priority right now because of many reasons, and because of the safety that we're seeing, which we're liking, and the broad applicability. I mean, it's a pan cancer drug, and it's hard to ignore how big this could be. With EXCEL though, we see some advantage of being able to do a few more patients on that. So our hope is to add in a few more patients. They haven't been added yet. We're in the process of amending our trial to allow more patients. But we're gonna have a pretty good picture of what happens on EpiCAM. So our intent is to drive some additional patients there, but I will allow that EpiCAM could turn into something so exciting that we may decide to double down there. But for now, yes, that's our plan. Gotcha,

thanks for that. And my last question is regarding the BD, or strategically wise. So besides you think about to part out the RR2 and CTLA-4 program, are you open to any other strategy to maximize the stock shareholder value?

Oh yeah, I mean, certainly we do have a strategy to be open if a partner decided that they wanna drive Axel instead of RR2. Both are pretty exciting. We're also always looking at backup strategies. We're partnering timing sometimes as we've learned, it can be hard to exactly forecast, but we're definitely doing both of those things.

Gotcha, yeah, thanks for taking my question and congrats on the progress.

I think they're coming in very nicely and I think it's kind of rare in this

world where everything is working.

Thank you.

Thank you, it

appears that we have no further questions at this time. I will now turn the program back over to Jay Short for any additional or closing remarks.

I just wanna thank you all for your time and I think hopefully you've heard some of this data. We're pretty excited about the differentiation we're seeing in the RR2 programs. EpCab we think we're pioneering there. We also think Axel is also as well as CTLA-4 are showing the differentiation that we expected from CAB and I think that's gonna translate into partnerships sooner than later. So thank you for your time.

Thank you, this does conclude today's program. Thank you for your participation. You may disconnect at any time.